A visibility splay you cannot control.

What the inspector decided

Pandy Lane is described in the decision as a narrow rural road linking Bedwas, Maesycwmmer and the Twyn Shon Ifan junction. The property previously shared a short driveway with its neighbour. The scheme removed part of the roadside hedge to form a new access and a parking area for two cars. At the site visit, part of the hedge had already been removed and the access works had begun (paragraphs 14 and 15).

The appellant contended that the lane was lightly trafficked, that the access was spacious and safe, and that adequate visibility could be secured by a condition requiring management of the hedge. The council's position was that adequate visibility splays for emerging vehicles had not been demonstrated (paragraphs 16 and 17).

The inspector's finding is at paragraph 18. The splay would extend across part of the neighbour's frontage and other land outside the appeal site. While it was unlikely that the shared access would be obstructed, there was no certainty that the splay would remain clear. Any obstruction would restrict drivers' views and could give rise to conflict. The proposal was therefore contrary to policy CW3 of the local development plan and to TAN 18 (paragraph 19).

The question of control

The reasoning on this point is brief, but it reflects a familiar principle. A planning permission runs with the land and is not time-limited in its effect. The relevant question is therefore not whether the present neighbours are likely to keep the splay clear, but whether its availability can be secured for as long as the access is in use. Ownership may change, and a future owner is free to plant, park or build within their own frontage.

The decision does not expressly address the hedge management condition. It is, however, difficult to see how such a condition could have met the concern. A condition may properly require an applicant to keep land within their control free of obstruction. Imposing an equivalent requirement over a third party's land raises obvious difficulties of enforceability and reasonableness. That is our reading rather than the inspector's stated reasoning, but it is consistent with the conclusion reached.

The lightly trafficked argument

The argument that a road is quiet goes to the frequency of potential conflict, not to whether the conflict arises at all. A Bridgend decision of April 2025 at Belmont Close, Maesteg, illustrates the point. A 1.45-metre wall built up to an access on a sharp bend was found to obscure visibility for vehicles entering and leaving. The inspector accepted that the street was narrow, residential and lightly trafficked, but concluded that the wall would cause unacceptable harm to the safety of pedestrians, cyclists and drivers. An outbuilding on the same plot, set away from the bend, was allowed.

Neither decision suggests that traffic volume is irrelevant. Both indicate that it will rarely be sufficient where the visibility itself is deficient or cannot be relied upon.

What evidence was missing

The decision records no splay dimensions, no evidence of vehicle speeds and no agreement with the adjoining owner. It would be speculative to say the outcome on this issue would have been different with that material. It is fair to say that each would have given the inspector something more than assertion on which to proceed.

• Recorded speeds. On a narrow lane, measured speeds may support a reduced splay length, which might fall within the appellant's own land or the highway.
• The extent of the highway. Land that appears to form part of a neighbour's frontage is sometimes highway verge, in which case the splay may already be protected. A highway boundary search would settle that.
• An agreement with the adjoining owner. A planning obligation or a registered agreement binding the neighbour's title can provide the certainty that a condition cannot.
• An alternative position. A modest change in the location of the access can sometimes bring the splay within land the applicant controls.

None of these would have addressed the separate finding of harm to character and the Special Landscape Area, which would itself have justified dismissal.

Practical points

• Plot the splay against title and highway records before the access position is fixed, so that any reliance on third-party land is identified at the outset.
• Support the splay length with evidence. In Wales, TAN 18 and the authority's own guidance provide the framework. Speed data allows the appropriate standard to be applied rather than argued.
• Secure any land outside your control through the highway, a binding agreement or a revised layout, rather than through a condition that may not be capable of enforcement.
• Avoid carrying out works before permission. Here, the hedge removal and access works were already under way, and an access built without consent may have to be reversed.
• Distinguish what can be conditioned. In this case, landscaping and ecology were capable of being dealt with by condition. Highway safety was not. Identifying that distinction before the appeal allows the evidence to be directed accordingly.